Postal rates have been steadily increasing for the past several years and postage costs have become a greater and greater burden for mailers. To help in controlling postage costs, mailers, particularly larger mailers, have a need for a means to account for postage expended on a departmental and/or a customer basis in order to maintain closer control of postage costs and to facilitate charge back of such costs. Such mailers will typically have one or more postage meters. (Postage meters are well-known devices which imprint appropriate postal indicia and account for postage expended up to a pre-set limit.) Given the need to control postage costs through closer departmental or customer accounting and the fact that postage meters only record total postage expended, there is a need for systems to facilitate accounting for the postage expended through a postage meter.
One such system is disclosed in U.S. Pat. No. 4,319,328, For: Postage Cost Recording System, To: Eggert, Issued: Mar. 9, 1982. In the system disclosed, a postage computer sets a mechanical postage meter in accordance with information received from a postal scale and records postage for each item metered in response to a signal from a "item feed sensor". Other such systems include the Electronic Accounting System (EAS) and the Electronic Journal Printer (EJP) marketed by Pitney Bowes Inc. of Stamford, Connecticut.
It will be apparent to those skilled in the art that an important feature of such systems is data security. Clearly such systems will fail of their object if data may be lost or altered by power failure or transients, or through inadvertent or fraudulent operation of the system. Heretofore, such systems have relied upon the use of nonvolatile memory to secure data during power failure and on the use of special supervisory access codes for functions such as editing of accounts. One example of a technique for data security is disclosed in U.S. Pat. No. 4,323,987 to Holtz et al. The system taught in this patent includes a back-up battery power supply which is connected to a volatile memory if an impending power failure is detected. The system further includes a timer which measures the duration of the power failure and initiates a transfer of the memory contents to an external device such as a printer for later recovery.
While systems using such techniques have been generally successful, some problems have remained. Despite the use of non-volatile memory power failures or transients which occur at critical times such as during print out of account records or editing of account records, may still result in the loss of account data. Also, it has been found that operators have in practice often obtained the supervisory access code and erroneously edited account records.
Such erroneous editing of account records is a particular source of problems and costs for vendors. Supervisors, perhaps unaware that account records were being inappropriately edited by operators, would discover inexplicable errors in various account records and request a service call by the vendor's field service technician to "fix" the system. The technician, of course, would find nothing wrong with the system and, since the erroneous editing was successfully completed, would not find edit flags indicating that accounts had been edited. Such futile service calls not only represent an unnecessary cost for the vendor and/or the customer but also create an image of poor product reliability, and strain customer relations.
Thus, it is an object of the subject invention to provide a system for accounting for postage expended by a postage meter.
More particularly, it is a further object of the subject invention to provide such a system which is protected against erroneous or fraudulent editing of account records.